Our ProgramFor many patients who have Parkinson’s disease, essential tremor, dystonia or other movement disorders, otherwise useful medications cannot prevent troublesome or even disabling symptoms. For these patients, the surgical intervention of deep brain stimulation (DBS) is an option.
Deep brain stimulation is a technique in which electrical current is applied through a wire placed in very specific locations in the brain. DBS is approved by the Food and Drug Administration for the treatment of Parkinson’s disease, essential tremor, dystonia and obsessive compulsive disorder. The technique is believed to disrupt abnormal electrical signals in the brain that are caused by these illnesses.
The USC Deep Brain Stimulation Center at Keck Medicine of USC in Los Angeles offers Southern California’s most comprehensive care for patients requiring deep brain stimulation. The Center’s team of health-care professionals provide the highest quality care to patients considering DBS for treatment. It also conducts advanced research in these and other disorders and is a National Parkinson Foundation Center of Excellence, one of only 39 such centers nationwide (and the only designated center in Southern California).
The USC Deep Brain Stimulation Center at Keck Medicine of USC in Los Angeles is an interdisciplinary program that draws from adult and pediatric neurologists, neurosurgeons, psychiatrists, nurse practitioners, clinical psychologists, neuropsychologists and social workers. It also collaborates with the Parkinson’s Disease and Movement Disorders Center and the Intraoperative Neurophysiological Monitoring Program.
As part of a renowned university-based medical center, members of the center conduct research in other projects exploring such areas as behavioral side effects of DBS and medication for Parkinson’s disease; the effect of exercise in Parkinson’s disease; treatment of dyskinesias in Parkinson’s disease; and outcomes of DBS in patients with Parkinson’s disease, essential tremor, dystonia and obsessive compulsive disorder.
ConditionsMany patients with Parkinson’s disease, essential tremor, dystonia and other movement conditions can suffer from troublesome or even disabling symptoms despite advanced medical therapy. For these patients, surgical intervention with deep brain stimulation (DBS) offers an alternative treatment.
Parkinson’s disease (PD) is a neurologic disorder that causes degeneration of parts of the brain that are intimately involved with coordination and mobility. Patients suffer with prominent movement abnormalities. PD affects about one percent of all people over 55 years of age. The main movement problems are slowness of movement (bradykinesia); involuntary shaking parts of the body, usually a limb, (rest tremor); muscle stiffness (rigidity); and abnormalities of walking and balance. Other symptoms separate from the movement problems can arise as well, such as constipation, sleep difficulties, loss of sense of smell/taste, depression and lightheadedness. The symptoms of Parkinson’s disease gradually worsen over time. The cause of Parkinson’s disease is not known, but is widely believed to involve a combination of both genetic and environmental factors. A specific gene or environmental cause has not yet been identified. Parkinson’s disease has no cure, but there are many effective treatments.
Dystonia is a medical term for involuntary twisting, turning or spasm that can occur in any skeletal muscle. Dystonia may present as a primary disorder or as a component of another disorder. Tremor is defined as a, rhythmic oscillation or shaking movement. Essential tremor is a postural or kinetic tremor predominantly of the upper extremities but can also affect the voice and head and neck. It is also known by other names, including: benign essential tremor or benign familial tremor. It is the most common form of tremor, affecting five percent of the population. Essential tremor tends to worsen gradually, over many years. Some patients with essential tremor have handwriting that is a shaky and sometimes illegible. Patients often have trouble using eating utensils or drinking liquids because the tremor causes them to spill food or drink. Stress- or anxiety-provoking situations can worsen tremors.
Obsessive-compulsive disorder (OCD) is a disease characterized by obsessions, which are unwanted thoughts, images and impulses that “pop” into a person’s mind, generate anxiety and lead to compulsions, or neutralizing actions aimed to reduce the distress generated by the obsessions.
We evaluate and treat appropriate patients with deep brain stimulation therapy and provide continuing psychotherapeutic services for those eligible for DBS (if other treatments have been unsuccessful).
Treatments and Services
The Deep Brain Stimulation Center at Keck Medical Center of USC in Los Angeles has the most comprehensive team of deep brain stimulation experts in the fields of movement disorders and psychiatry in Southern California. All DBS centers offer surgery, but few provide the breadth and depth of expertise required to treat all aspects of disease, whether it is Parkinson’s disease, essential tremor, dystonia or obsessive-compulsive disorder (OCD).
Alongside the USC Parkinson’s Disease and Movement Disorder Center, we have assembled a team of neurologists, neurosurgeons, psychiatrists, nurse practitioners, clinical psychologists, neuropsychologists and social workers that collaborate to evaluate, diagnose and treat patients with Parkinson’s disease and other parkinsonian syndromes, essential tremor, dystonia, Tourette’s syndrome and other tic disorders, myoclonus, Huntington’s disease, ataxia and other movement disorders. We are also a National Parkinson Foundation Center of Excellence. Once other medical and psychological treatment options prove ineffective in treating a patient’s movement disorder, we then consider deep brain stimulation (DBS) as an option.
The brain’s subthalamic nucleus (STN) and the globus pallidus interna (GPi) become overactive in patients with Parkinson’s disease. The thalamus is overactive in patients with essential tremor. The part of the brain that is overactive in patients serves as the target for DBS.
Deep brain stimulation (DBS), is performed with an electrode (a thin wire) that is permanently implanted in a target area of the brain. A low-intensity current is continually pulsed to clinically deactivate the area without causing permanent damage. DBS provides a reversible and adjustable surgical treatment. By stimulating small targets in the brain, DBS blocks abnormal electrical signals, which cause disabling symptoms such as tremor or dystonia. Excessive abnormal activity in these nuclei is “corrected” by the electrical stimulation of DBS. DBS does not affect the underlying disease process and is not a cure for the diseases it treats. However, it can dramatically improve the disabling symptoms of Parkinson’s disease, essential tremor, dystonia and OCD.
Patient InformationAll DBS candidates at USC undergo a complete pre-operative evaluation, including neurological examinations, psychological and cognitive assessments and a brain MRI. Patients will be scheduled to meet their neurosurgeon and movement disorder neurologist. If a patient is receiving DBS for OCD, he or she will meet with our OCD specialists. We will work closely with the referring community neurologist or primary care provider to ensure a cooperative and comprehensive evaluation.
The surgical procedure
All patients being considered for DBS surgery will meet with each team member for a pre-operative screening. An MRI of the brain is obtained, either the morning of surgery, or up to a few months prior. On the day of surgery, the patient is admitted to the hospital and brought to a pre-operative holding area. A mild sedative is administered, and a metal scaffolding framework is affixed to the head. A CT scan is then obtained with the patient’s head in the frame. This shows specific brain regions and their location in relationship to parts of the metal frame. The CT scan images and the previously-obtained MRI images are then used to calculate the best path for the electrode to reach the target.
Local anesthetic is used to numb the scalp, and an incision is made, exposing a small portion of the skull. A small hole is drilled through the skull that is 14mm in diameter. A microelectrode is then inserted into the brain and slowly advanced to the target. During this process, electrical signal of individual brain cells that are near the tip of the electrode can be detected and recorded. These signals differ depending upon what part of the brain is being monitored, and thus can help to determine which structure the electrode is passing through. It also can help to identify the target tissue once the electrode reaches it. During this part of the procedure, the patient is awake to better measure the electrical activity (being asleep or unconscious changes the brain cell activity). Sometimes, we will have the patient perform simple tasks during the surgery to monitor changes that are induced in the electrical signal.
When we are in the correct location, the stimulating electrode is tested by running an electrical current, producing an effect similar to what would occur after the full system is implanted. Once we are confident that the location is correct, the electrode is affixed to the skull and the incision closed. If indicated, the same procedure can be performed on the other side of the brain (in some cases, however, the other side is delayed until a later date to ensure that things go well with the first side). Usually the patient will be discharged home the following day. The implantable pulse generator (battery) is inserted beneath the skin of the chest wall about one week later, a procedure that does not require hospital admission.
Patients with Parkinson’s disease and essential tremor may feel an immediate improvement in their symptoms, termed the “lesion effect,” which occurs in relation to immediate post operative swelling. This beneficial effect may wane in the next one to two weeks before the battery is placed in the chest, and the device is turned “on”. After the battery is placed, an appointment is scheduled for wound checks, removal of stitches and a series of programming sessions by our nurse practitioner. These programming sessions are at intervals of every two to three weeks, with complete optimization of DBS settings taking two to three months. During this time medications may be reduced and disease symptoms should continue to improve. Incisions should be kept clean and dry for one week following surgery. Once the incisions are healed (two to three weeks), you may resume all normal activities, including exercise and swimming.
After recovery from the surgery and optimization of DBS settings, it is expected that patients may return to their pre-operative activity level without major restrictions. They are given a hand-held Access Patient Controller, which will enable them to check the device periodically and turn it ON and OFF as needed. The USC DBS team will see patients once or twice a year at minimum to check on battery status, with routine follow-up being provided by the referring neurologist or psychiatrist.
Rarely, strenuous activity or accidental trauma (such as a car accident or fall) can cause lead breakages, which may need to be repaired surgically. Security devices at the airport or in stores can also accidentally turn off the device, but this is not dangerous.
Frequently Asked Questions
What are the risks and complications?
Stroke – any time something is inserted into the brain, there is a risk of bleeding, causing a stroke. At USC, the risk of stroke is less than 0.5 percent, which is well below the national average. Furthermore, we use O-arm technology (a specialized, real-time X-ray), which allows immediate identification and assessment of possible problems. Since the patient is awake during surgery, changes in the clinical condition are easily monitored and can immediately alert the physicians and nurses to a possible stroke, allowing quick and decisive action.
Infection – in comparison with other neurosurgical procedures, risk of infection is low. At USC, the infection rate is about 3 percent. If infections occur, they can be treated with oral and intravenous antibiotics. On rare occasions, wires and the implant will need to be removed while the infection is treated to ensure that it is completely eradicated. The hardware can be replaced after the infection clears, which is usually after about three months.
Wire breakage – this is a rare event, occurring at USC less than 1 percent of the time. It is typically caused by unusually severe twisting of the DBS wires with strenuous activity. If the broken wire is not actually needed for therapeutic effect and the rest of the system remains intact, the hardware can be left in place and monitored. If a wire that is being used for therapeutic stimulation breaks, the treatment requires another operation and replacement.
Wire movement – also rare, wire movement is the pulling back of the deep brain stimulator electrode out of its target in the brain. When this occurs, there is failure of the DBS to provide good effect. Treatment of this complication requires replacement of the electrode.
Cognitive impairment – most studies of cognitive function indicate no change in global cognition following surgery. As part of our preoperative assessment, every patient undergoes neuropsychological testing to identify any cognitive abnormalities. In our experience, those with some degree of memory loss prior to surgery may develop a mild, mostly transient, decline in memory after surgery.
Uncomfortable side effects of stimulation – infrequently, patients may experience side effects of stimulation, including pulling of the face or limb, numbness, tingling or changes in mood. This occurs when the electrode tip is placed at the edge of the target, having the undesired effect of stimulating brain pathways outside of the targeted area and causing these side effects. This is generally avoided by conducting a “test” stimulation during surgery to confirm that the electrode is in the correct location. The electrode can be moved if the test stimulation causes these side effects. After surgery, programming adjustments of the stimulator settings can generally avoid uncomfortable side effects. Rarely, the electrode may need to be repositioned after the initial surgery if the side effects cannot be eased.
Am I a good candidate for DBS?
For all disorders
You may be a good candidate for DBS if you:
- Have intact cognitive and intellectual function. Patients with dementia have difficulty tolerating the surgery, understanding and cooperating with post-operative care and may have further intellectual decline following the surgery.
- Are in good general health. Uncontrolled medical conditions such as hypertension or cardiac disease increase the risk and limit the benefit of DBS. Although there is no age limit, younger patients (below the age of 75) tend to benefit more from DBS surgery.
You may be a good candidate for DBS if you:
- Have a confirmed diagnosis of Parkinson’s disease. Several diseases mimic the symptoms of Parkinson’s disease. Talk to your neurologist if you have a question about your diagnosis. A referral to a movement disorder specialist can help confirm your diagnosis.
- Respond well to levodopa/carbidopa (Sinemet®). DBS surgery offers to extend the period of time during the day spent in your “on-medication” state. It rarely does better than your best “on-medication” state, with the exception of tremor, which may improve with DBS despite not responding to medication. DBS surgery is best for patients who function well in their “on” state, but have a significant amount of “off-medication” time, or excessive dyskinesias.
- Have excessive side effects from your medication. Long term use of levodopa and other medications for Parkinson’s disease can cause hallucinations, behavioral side effects and disabling dyskinesias. DBS can allow you to decrease your medication by 30-50 percent, while improving your symptoms of Parkinson’s disease.
You may be a good candidate for DBS if you:
- Have a confirmed diagnosis of essential tremor. Several diseases mimic the symptoms of essential tremor. Talk to your neurologist if you have a question about your diagnosis. A referral to a movement disorder specialist can help confirm your diagnosis.
- Have a disabling tremor, which interferes with your activities of daily living and quality of life.
- Have excessive side effects to your medications. DBS can dramatically improve the tremor, while allowing you to decrease or even discontinue medications.
You may be a good candidate for DBS if you:
- Have focal, segmental or generalized dystonia. Dystonia is a medical condition in which there is abnormal, involuntary and sustained muscle pulling.
- Have disabling and painful dystonia, which interferes with your activities of daily living and quality of life.
- Have excessive side effects to your medications. DBS can dramatically improve dystonia, while allowing a decrease in medication used to treat dystonia.
You may be a good candidate for DBS if you:
- Have suffered from OCD symptoms for greater than one year, with symptoms that have caused a significant impairment in function, usually characterized by a score of 28 or greater on the Yale-Brown Obsessive Compulsive Scale (YBOCS).
- Have had at least 3 trials of anti-obsessional medications, at maximum recommended/tolerated dose for at least 12 weeks, among the five that have been approved for OCD. At least one of these medications should have been clomipramine. In addition, you should have had augmentation trials with a neuroleptic and a benzodiazepine medication.
- Have had at least one adequate trial of cognitive-behavioral therapy (CBT), including at least 20 sessions with therapist-guided behavior therapy (exposure and response prevention).
- Have excessive side effects to your medication(s), making it difficult for you to control your OCD symptoms enough for you to function adequately. DBS can improve OCD, while often allowing you to decrease or even discontinue medication(s).
What are the costs of DBS surgery?
DBS surgery is an FDA-approved therapy for Parkinson’s disease, essential tremor, dystonia and OCD. Most insurance companies, including Medicare, will cover at least a portion of the cost of the pre-surgical evaluations, the surgery and the follow-up visits. Individual insurances will provide varying coverage. You should contact your insurance provider for more information on DBS coverage.
ResourcesThe Deep Brain Stimulation Center at Keck Medical Center of USC in Los Angeles has a wide range of resources for patients, including support groups, services and clinical trials.
Patient Support Groups
We offer a USC DBS Support Group. Our vision is to provide an open educational forum for all individuals with Deep Brain Stimulators, their families, friends and caregivers. Our goal is to empower you by expanding your knowledge and understanding of Deep Brain Stimulation. We support you by being here as a resource at every step of your journey.
At each meeting, we have a formal presentation. The presenters have included specialists in neurology, speech therapy, physical therapy and social services. All meetings are moderated by a nurse practitioner. Time is allocated for discussion and questions at the end of each session.
The USC DBS Support Group is open to all individuals with DBS, their families and caregivers. For information, contact (323) 442-7641.
The center is home to the largest clinical trials program in Southern California for Parkinson’s disease and dystonia. The center participates in many clinical trials to expand our understanding of important issues for patients undergoing Deep Brain Stimulation therapy. We are currently working with our DBS patients to explore their expectations before and after Deep Brain Stimulation Therapy. We are also examining outcomes based on a comparison of our patient’s self-reporting of symptoms and clinician’s evaluation after DBS placement.
Our physicians also conduct research in other projects exploring areas such as behavioral side effects of DBS and medication for Parkinson’s disease, the effect of exercise in Parkinson’s disease, treatment of dyskinesias in Parkinson’s disease, and outcomes of DBS in patients with Parkinson’s disease, essential tremor, dystonia and OCD.
There is a great deal of promising research in the field of Parkinson’s disease. It is one of the most active areas of investigation into a specific disease. At any time, there are a number of clinical trials being conducted to examine new treatments. These can include new medications, gene therapy, stem cells, exercise regimens and other therapies. If you would like to learn more about clinical trials, please click here.
Practicing LocationsKeck Hospital of USC
USC Healthcare Center 2
USC Norris Comprehensive Cancer Center and Hospital
Additional Faculty Physicians
Quyen N. Luc, MD
Terry Sanger, MD, PhD
Additional Team Members
Nasrin Esnaashari MSN, CCRN, CNS CNP